The contract certainty working party is to review its code of practice to force insurers to issue commercial wordings within 20 days.
It comes after the FSA raised concerns about the disparity between insurers' and brokers' compliance data.
Although insurers' data showed 90% of commercial contracts issued were contract certain, only 63% of contracts issued by brokers were done so within the 30 days specified by the code of conduct.
Clive Wood, Royal & SunAlliance head of UK regulatory risk and compliance who sits on the non-subscription working group, said many insurers were issuing contracts too late for brokers to issue policies on time.
"Insurers have got to get contracts out by the 30th day, but they are not giving enough time for the broker to issue the policy. So the code will be changed in the new year, when insurers will be given 20 days to get the contract to the broker."
Wood added: "This is the single biggest challenge facing insurers, brokers and buyers."
Steve White, regulation and compliance manager at Biba, said problems were arising when policies issued by insurers were deemed to be inaccurate by brokers.
"There is a big difference between what insurers and brokers are reporting because the policies are reported as being inaccurate.
"The problem is we have antiquated technology which means there is a lot of rekeying and mistakes are made. Anything that insurers can do to stop this will help brokers."
One senior broker blamed software houses for neglecting contract certainty in broker systems. "At the moment there just aren't the provisions available, and this is making it more difficult for smaller brokers to measure," the source said.